Biology subjects

Kanao, T.

Publications and source records attributed to Kanao, T..

4 recordsLinked to original sources

bioRxiv2025

Diversification of pre-mating behaviors through temporal reordering of components

Many biological processes, including mating behavior, are structured as ordered sequences in which each step enables the next. Diversity of such processes usually arises through the addition or loss of components rather than through changes in their order, since reordering can disrupt functional integration. Here we show that reordering of the steps associated with termite nuptial pairing can generate behavioral diversity. In most termites, dispersed adults shed their wings before initiating tandem pairing, as wings interfere with communication between females and males. However, we found that in the Australian termite, Microcerotermes nervosus, tandem running occurs prior to wing shedding, and the act of tandem running itself facilitates dealation. Video tracking revealed that wing removal improves movement coordination, and comparative analysis of sympatric species showed that M. nervosus exhibits much higher tandem stability than others. These results suggest that enhanced movement coordination of this species may have potentiated step reordering. Our findings demonstrate that even functionally conserved sequences can be reorganized and that overcoming such constraints can open novel pathways for behavioral diversification.

animal behavior and cognition↗

bioRxiv2025

Observation of tandem running behavior in mating pairs of Asian dampwood termite, Hodotermopsis sjostedti

As a social insect, termite colonies can grow to a group of millions of individuals, yet all colonies start from a single mating pair. Recent studies indicate that the pair formation process shows a large diversity among species, especially in basal lineages. Thus, comparative information is integral to estimating the ancestral state of this essential stage of the termite life cycle. The Asian dampwood termite, Hodotermopsis sjostedti, has been well-studied as a model basal termite of caste differentiation processes. Yet, their pair formation remains undocumented. In this study, we found that mating pairs of H. sjostedti show clear tandem running behavior. Both females and males played a leading role, with females showing more leader roles, and they switched their leading roles even within the same pair. We also found that dish size affected tandem movement coordination; pairs showed faster and more stable tandem running in a larger dish. We provide a tracking dataset of 17 body parts, including antennal and leg movements during tandem runs, which can be utilized in future comparative studies. This study supports the idea that tandem running existed in the early ancestors of termites and sheds light on the origin of termite mate pairing.

animal behavior and cognition↗

bioRxiv2021

Neoisoptera repetitively colonised Madagascar after the Middle Miocene climatic optimum

Madagascar is home to many endemic plant and animal species owing to its ancient isolation from other landmasses. This unique fauna includes several lineages of termites, a group of insects known for their key role in organic matter decomposition in many terrestrial ecosystems. How and when termites colonised Madagascar remains unknown. In this study, we used 601 mitochondrial genomes, 93 of which were generated from Madagascan samples, to infer the global historical biogeography of Neoisoptera, a lineage containing upwards of 80% of described termite species. Our results indicate that Neoisoptera colonised Madagascar between seven to ten times independently during the Miocene, between 8.4-16.6 Ma (95% HPD: 6.1-19.9 Ma). This timing matches that of the colonization of Australia by Neoisoptera. Furthermore, the taxonomic composition of the Neoisopteran fauna of Madagascar and Australia are strikingly similar, with Madagascar harbouring an additional two lineages absent from Australia. Therefore, akin to Australia, Neoisoptera colonised Madagascar during the global expansion of grasslands, possibly helped by the ecological opportunities arising from the spread of this new biome.

ecology↗

bioRxiv2016

A defensive body plan was pre-adaptive for termitophily in the rove beetle tribe Termitohospitini (Staphylinidae: Aleocharinae)

Termitophily--the symbiosis of organisms with termite societies--has evolved a disproportionate number of times within the rove beetle subfamily Aleocharinae (Staphylinidae). Among aleocharine termitophiles, defensive (limuloid) and mimetic (physogastric & physothoracic) body forms have evolved convergently, but due to lack of a comprehensive aleocharine phylogeny, the context in which termitophily and associated adaptations evolve is unknown. We present the first example of a robust, morphology-based phylogenetic placement of an exclusively termitophilous tribe, the Termitohospitini. Termitohospitini is recovered to be nested within Myllaenini sensu nov, and sister to Myllaena (new synonymy). Furthermore, we also recovered the small tribe Masuriini nested within Myllaenini sensu nov (new status).\n\nReconstructing ecological transitions within this clade, we present evidence that the stem lineage of Myllaenini sensu nov invaded intertidal marine habitats, the common ancestor for Myllaena + Termitohospitini then transitioned to freshwater riparian habitats, with Termitohospitini alone subsequently shifting to termitophily. We conclude that: (1) Termitohospitini was ancestrally a limuloid-bodied riparian inhabitant; (2) a limuloid form may have been pre-adaptive for defense against host attack during the evolution of termitophily; (3) the strongly tapered abdomen of an ancestral limuloid body was a constraint on the evolution of physogastry, leading to the emergence of the unusual physothoracic body form observed in termitohospitines that likely integrates these obligate termitophiles to life inside termite colonies.\n\n\"one of the most astonishing spectacles in all natural history.\" -- Richard Dawkins

evolutionary biology↗